exador: What I meant to imply is that currently there is a disincentive to run a gas guzzler due to petrol taxes. With the tax removed, EVs will be even less attractive.
Currently petrol vehicles that use 9.5L/100km are paying FET equivalent to 7.6c/km, the same as diesels and EVs. If this is the sum total of the taxation changes it will benefit high consumption vehicles with cheaper petrol but the same RUC km rate as economical vehicles. In order to avoid the tax change becoming a windfall to 'gas guzzlers' some form of carbon tax needs to be added and it looks like the 12c per litre tax rise will be the first part of this.
It will be good too if the RUC purchasing system is upgraded to remove admin charges as these continue to most heavily penalise those who purchase RUCs in minimum quantities.